Wallets that use Electrum as their block source face greater difficulty acting as a Payjoin receiver.

[arminsabouri]

We rightfully guide applications to use testmempoolaccept at the check_broadcast_suitability typestate check. For reasons unknown to me electrum implementations do not support a testmempoolaccept equivalent. It should be relatively easy to support this method as most implementations end up using bitcoind's JSON rpc interface.

For example it took me 10 min to add and test support for electrs. romanz/electrs@master...arminsabouri:electrs:test-mempool-accept .

[DanGould]

Yes this one goes way back

[DanGould]

The receiver's Original PSBT broadcast check is mostly there to prevent an automated payment processor from being vulnerable to probing attacks. In the Liana use case, I don't think it's as important since you'll probably know exactly who your counterparty is and communicate the bitcoin URI out of band with them directly. For that reason, I think Payjoin could work in Liana while bypassing the check for electrum. We should still get the support in if it's possible, but it's not a strict blocker.